1. Field of the Invention
The present invention relates to auto reverse type tape players and more particularly to an auto reverse type tape player capable of performing endless play using a battery as a power supply.
2. Description of the Background Art
An auto reverse type tape player is capable of selectively switching between a one-cycle mode where a tape driving motor is stopped after one cycle of forward play and reverse play, and an endless mode where the above-mentioned cycle is repeated without stopping the motor. A conventional auto reverse type tape player has a switch for setting the endless mode and when the user desires to repeat forward play and reverse play, he or she operates the above-mentioned switch to set the endless mode.
In the auto reverse type tape player of the above-mentioned structure, it is necessary to provide a switch dedicated to setting of the endless mode in an operation portion. Consequently, the structure of the operation portion is complicated. In addition, operability is not good because after a play button is operated, it is necessary to operate the endless mode setting switch provided separately.
An auto reverse type tape player as described below is also known. This auto reverse type tape player includes: cam means rotating from a start position to an operation mode setting position via a mode selection position using a motor as a drive source; lever means engaged with the cam means and moving according to the rotation of the cam means, thereby switching among operation modes of a tape; drive means for moving the lever means to change a positional relation between the cam means and the lever means; selection position detecting means for detecting the cam means in the mode selection position by determining that elapsed time after start of movement of the cam means attains a preset reference time; and control means responsive to a detection signal from the selection position detecting means for controlling movement of the drive means based on an inputted operation mode signal.
In the auto reverse type tape player of such a structure as described above, the time required for the cam means to rotate from the start position to the mode selection position by the motor under the reference voltage is calculated and this time is set as the reference time. In consequence, problems as described below are involved. In a tape player using a battery as a power supply, the voltage supplied to the motor changes according to change in the battery capacity Consequently, the rotation speed of the motor also changes. The conventional tape player detects that the cam means is in the mode selection position, by determining that the elapsed time after start of movement of the cam means attains the preset reference time. However, if the rotation speed of the motor changes, the time required for the cam means to attain the mode selection position also changes. Thus, the conventional tape player does not have a good precision for detection of the mode selection position and involves irregularity in timing for changing the positional relation between the cam means and the lever means.
Some improvement might be made with respect to the above-described disadvantage if a range of timing for switching of operation modes is enlarged. However, there is a limitation in increasing such range of timing and this method is not so effective. In addition, if the range of application of the voltage supplied to the motor is set narrow, there is another disadvantage that the time of use of the battery is shortened.
An auto reverse type tape player having first and second oscillation mechanisms is also known. In this auto reverse type tape player, the first oscillation mechanism includes a play gear engaging with motor drive gear means, and the second oscillation mechanism includes a fast forwarding gear engaging with the motor drive gear means. The first oscillation mechanism is provided to be movable among a forward play position enabling the play gear to engage with take-up reel gear means, a reverse play position enabling the play gear to engage with feed reel gear means, and an intermediate position not causing engagement of the play gear with the take-up reel gear means or the feed reel gear means. The second oscillation mechanism is provided to be movable among a fast forwarding position enabling the fast forwarding gear to engage with the take-up reel gear means, a rewinding position enabling the fast forwarding gear to engage with the feed reel gear means, and an intermediate position not causing engagement of the fast forwarding gear with the take-up reel gear means or the feed reel gear means.
Each of the above-described first and second oscillation mechanisms operates by rotation force of the motor drive gear means and thus at the time of switching from the stop mode to the play mode for example, not only the first oscillation mechanism but also the second oscillation mechanism operates. At this time, there is no particular problem if the first oscillation mechanism reaches the forward play position or the reverse play position to set the components in the play mode before the second oscillation mechanism reaches the fast forwarding position. However, if the second oscillation mechanism reaches the fast forwarding position before the first oscillation mechanism reaches the forward play position due to deviation in timing, the fast forwarding mode is temporarily set and particularly in the following situation, a considerable problem occurs.
More specifically, if the fast forwarding state is set during mode switching operation in the state where the tape cassette set in the tape player already attains a tape end, the take-up reel support is locked to apply an excessive load to the motor. In this case, switching of modes cannot be performed smoothly and it is feared that switching of modes cannot be made.